Summary: 404
Journal of Vertebrate Paleontology 23(2):404­419, June 2003
2003 by the Society of Vertebrate Paleontology
THE LATE CRETACEOUS PLACENTAL MAMMAL KULBECKIA
J. DAVID ARCHIBALD1
and ALEXANDER O. AVERIANOV2
1Department of Biology, San Diego State University, San Diego, California 92182-4614, U.S.A.;
darchibald@sunstroke.sdsu.edu;
2
Zoological Institute, Russian Academy of Sciences, Universitetskaya nab., Saint Petersburg 199034, Russia
ABSTRACT--Kulbeckia, a placental mammal from the late Turonian­Coniacian (Late Cretaceous) of Uzbekistan,
was originally placed in the monotypic Kulbeckiidae. Important new material indicates that Kulbeckia is the basal most
memberof ``Zalambdalestidae'', which also includes Zalambdalestes, Barunlestes, and the poorly known Alymlestes,
all from the Late Cretaceous of Asia. Kulbeckia shares with other zalambdalestids: a narrow, somewhat elongated
snout; procumbent, enlarged, and open-rooted medial lower incisor with enamel restricted to the more ventrolabial
surface; and anteroposteriorly compressed and centrally pinched molar trigonids. Commensurate with its 10-million-
year earlier age relative to other zalambdalestids, it is notable in its smaller size, probable retention of four lower
incisors, bifurcated or two-rooted lower canine, relatively smaller or absent diastemata between anterior teeth, more
lingually placed cristid obliqua, less reduced M3 and m3, and more dorsal and posterior placement of the angular
process in adults. Kulbeckia kansaica (Tadjikistan) and Kulbeckia rara (Uzbekistan) are regarded as synonyms of